Transformers: War for Cybertron
51 Achievements
14-18h
Unlikely Allies
Finish any level in Competitive Co-Op.
7.3%
How to unlock the Unlikely Allies achievement in Transformers: War for Cybertron - Definitive Guide
From the main menu:
1. Campaign -> Co-op Campaign -> Host a Game
2. Change Privacy to Invite, Change Scoring to On, Create Game
3. Select Checkpoint 1-10: Dark Energon (assuming you already beat Chapter 1, any other final chapter will do as well), Select your character
4. Start the game and head to the end. A final score screen should pop up after the chapter is complete and your achievements should unlock.
This is a way to get both Co-Op Campaign achievements in about ten minutes. The only pre-requisite is that you've beaten Chapter 1 "Dark Energon", in Single Player.
Go into Co-Op Campaign and choose to host your own game. Make sure to set Competitive mode to ON. It's one of the few options you can choose before you actually start hosting. Choose Chapter 1, Checkpoint 10 (the very last checkpoint in Dark Energon). Set the difficulty to Easy.
You don't have to wait for anyone else to join, just start the game. You'll know Competitive mode is on because there is a scoring system under your name at the top of the screen. This last checkpoint is very short, and very easy, just shoot up all the Autobots in your way. On Easy difficulty, you should be able to take out everything very quickly.
At the completion of this checkpoint, you have now finished the level and you will get BOTH co-op achievements at the same time as long as you chose competitive. So you'll get the achievement for finishing a level in co-op, and finishing a level in competitive co-op even if you are playing by yourself.